U.S. Sen. David Vitter, R-La., who won a second Senate term last year without an endorsement from Republican Gov. Bobby Jindal, announced today he's "strongly endorsing" Jindal's re-election bid this fall.

Gerald Herbert, The Associated PressGov. Bobby Jindal, at press conference in May, is flanked by Sen. David Vitter, left, and Rep. Jeff Landry. Vitter Wednesday announced he was endorsing Jindal in his 2011 re-election bid.

But while Vitter credits Jindal with changing the "blatant corruption and cronyism" he says was once the norm in Louisiana politics, the senator does offer one subtle critique of the governor.

"To help Bobby become as engaged and bold as possible in his second term, we need a more conservative Legislature, particularly in the state Senate," Vitter wrote his supporters.

Vitter apparently was alluding to Jindal's frequent travels out of state to raise money for his own campaign, as well as to back other GOP candidates -- travel that brought criticism from Democrats who said he needs to engage more with the state's problems.

In praising Jindal, Vitter wrote: "He's honest and competent. He wants to make government leaner and smarter, not more bloated and intrusive."

Last year, Jindal repeatedly declined to endorse Vitter, saying it wasn't his role to take sides in federal election contests, though, in criss-crossing the country to raise money for his campaign and GOP causes, he endorsed other candidates for Congress.

Jindal never explained why he didn't endorse Vitter, though he attended one of the senator's Washington, D.C., fundraisers.

Democrats speculated the Republican governor, who is widely thought to have ambitions for national office, didn't want to embrace a candidate who in 2007 apologized for a "very serious sin" when his number appeared on a Washington escort service phone list.